Tension sensing device



: 1970 T. J. PERCONTI 3,501,105

TENSION SENSING DEVICE Filed OCT.- 9, 1968 2 Sheets-Sheet 1 INVENTOR.

ATTOR/V Y 8A6ENT THOMAS J. PERCONT/ March 17, 1970 T. J. PERCONTI 3,501,105

TENSION SENSING DEVICE I Filed Oct. 9, 1968 2 Sheets-Sheet 2 THOMAS J. PERCO/VT/ INVENTOR.

ATTORNEY 8 AGE/V7" United States Patent 3,501,105 TENSION SENSING DEVICE Thomas J. Perconti, Rochester, N.Y., assignor to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Filed Oct. 9, 1968, Ser. No. 766,242 Int. Cl. B6511 19/28, 25/10, 25/32 US. Cl. 24256.9 8 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a winding apparatus for a plurality of elongated flexible elements and, more particularly, to an apparatus for sensing tension variations in webs caused by malfunctions of the winding apparatus.

While the automatic winding apparatus, described in copending US. application Ser. No. 766,187, filed Oct. 9, 1968 entitled Automatic Winding Apparatus and Methods, is highly reliable in its operation, it has been found that it would be desirable to detect malfunctions in the equipment as soon as possible so that they may be corrected. Also, it has been found that it would be desirable to smooth out, or dampen, slight tension fluctuations during winding. In the aforementioned application, a plurality of webs are supplied from a slitting machine and simultaneously wound into rolls by a plurality of unitized windup devices. Each of the unitized windup devices includes means for automatically introducing successive cores within the nest of the winding drums, for cinching the leading end of a successive web around the core, and for winding the web onto the core to form a roll. The core introduction and web cinching occur during a start-up phase of operation. The roll is formed during the winding phase.

It has been found that there may be various malfunctions introduced during the startup phase of operation. As disclosed in said aforementioned application, a plurality of cores are contained in each of said windup devices. This arrangement may cause malfunctions if a core is oversized and jams in the winding device, or if there are an unequal number of cores in each one of the plurality of windup devices which are operated simultaneously. Also, malfunctions may occur during the startup phase if the leading end of the web is improperly guided around a nested core during cinching. The absence of tension on a web indicates that one of the above malfunctions has occurred during the startup phase of operation.

During the winding phase, malfunctions may result from several sources. For example, the webs may become tangled or broken between the slitting machine and the unitized windup devices. An individual windup device may malfunction such as when the bearings therein are insufiiciently lubricated. Also, malfunctions may be introduced by Webs which are slit to an improper width which causes binding between the roll being wound and the flanges which support the roll during winding. Since the webs are normally wound at a predetermined minimum level of tension, it has been found that a gradual as well as substantially instantaneous decrease below this level indicates that one of the above malfunctions has occurred.

While the above malfunctions infrequently occur in the automatic winding apparatus described in the aforementioned application, it should be apparent that it would be desirable to detect any of these malfunctions as soon as possible.

Accordingly, an object of the present invention is to avoid or minimize product waste or damage, damage to machine elements, and down time caused by various malfunctions in an apparatus for winding a first plurality of webs simultaneously and for subsequently winding a second plurality of webs simultaneously.

Another object of the present invention is to smooth, or dampen, slight tension flucuations in each web during winding.

Other objects and advantages of the present invention will be apparent to those skilled in the art by description of a preferred embodiment of the invention which follows.

The objects of the present invention are accomplished by providing an automatic winding apparatus, e.g. described in the aforementioned application, with means for sensing when the tension in at least one web is below a predetermined minimum tension. A preferred tension sensing means includes a movable guide roll for each unitized windup device. Each giude roll is mounted for rotation about its axis and for movement of its axis from a first to a second position. When the tension in the associated web is absent, or drops below a predetermined minimum level, the guide roll assumes the second position where the guide roll causes the activation of a photoelectric detecting means.

Reference is now made to the accompanying drawing wherein like reference numerals and characters designate like parts and wherein:

FIG. 1 is a side view, with portions broken away, of an individual unitized windup device and a schematic representation of a photoelectric detecting means according to one embodiment of the present invention.

FIG. 2 is a schematic representation of a plurality of adjacent unitized windup devices and a representation of the arrangement of the photoelectric detecting means according to one embodiment of the present invention.

FIG. 3, an enlarged cross-sectional view taken along line 33 in FIG. 1, shows some of the details of the tension sensing means according to one embodiment of the present invention.

FIG. 2 of the drawings is a schematic view of the upper and lower banks of a plurality of unitized windup devices 11. The windup devices are mounted on means such as rods 12 and are arranged to receive a plurality of webs S which are wound to form rolls 13. As described in the aforementioned copending application, the plurality of webs S may be supplied from a slitting device. As will be described in more detail in a further paragraph, the housing of each unitized windup device 11 has aligned holes 25. The plurality of unitized windup devices shown in FIGURE 2 are arranged so that a collimated light beam 14, supplied from light source 14, passes through the aligned holes 25 and illuminates a photocell 15 which is associated with means 16 for detecting the presence or absence of illumination. As will be described in a further paragraph, a malfuncion in any of the unitized windup devices 11 causes the interruption of light beam 14.

FIGURE 1 is a more detailed view of one of the unitized windup devicesshown schematically in FIG- URE 2. Only the portions of these devices which are needed for understanding the present invention will be described here. However, for further details of the construction and the operation of the windup device, reference may be made to the specification of the aforemen- 3 tioned copending US. application and to copending US. application Ser. No. 766,241 filed Oct. 9, 1968, entitled Surface Winding Device. I intend that the description in these applications be incorporated into the present description.

Each unitized windup device 11 includes a drive drum 1,8 and an idler drum 19 which form a nest for core 22 which is automatically inserted to initiate the winding phase. Drums 18 and 19 have flanges 18 and 19' respectively which partially embrace the sides of a web roll 13 during winding. Further, roll 21, having flanges 21, contacts the top of a web roll 13 as it winds when it has reached approximately 6 inches in diameter. The flanged drums and follower roll help to support the web roll 13 as it is being wound. Guide roll 41 is also mounted between side plates 17 of the housing. Guide roll 41, having flanges 41', is mounted so that it can move to cover aligned holes 25 in the housing in a manner which will be described in more detail in a later paragraph.

'During the startup phase of operation of each unitized windup device, top guide 23 rotates in a clockwise direction to introduce a core 22 into the nest between drums 18 and 19. Successive cores 22 are supplied from core chute 27. When the top guide 23 is in the extreme clockwise position, as seen in dotted lines in FIGURE 1, the automatic cinching of the leading end 24 of web S is accomplished. FIGURE 1 illustrates the point in the automatic cinching cycle where leading end 24 of web S is being guided by top guide 23 around the nested core 22. Once the leading end 24 is cinched completely around the core 22, top guide 23 is rotated to its extreme counterclockwise position, as shown in full lines in FIGURE 1, and winding of the web roll commences.

FIGURE 1 illustrates, in schematic form, circuitry which may be used to stop the winding apparatus if a malfunction is detected in any of the plurality of unitized windup device 11. Photocell (RC) 15 is normally illuminated by a beam of light 14'. If light beam 14 is interrupted by a guide roll 41 due to a malfunction in any of the unitized windup devices, then the photocell produces a signal, the long term components of which are filtered out at LT and amplified at A to operate a relay to disconnect the drive motor; the drive motor being mechanically coupled through drive means 26 to the unitized windup devices. Short term components of the photocell signal, as will occur as a result of intermittent (but not faulty) interruption of light beam 14', are filtered to ground at ST so as not to cause operation of the relay. Long term signal components are produced in the apparatus described in the aforementioned applications when more than approximately feet of web S passes around a guide roll 41 which is interrupting the beam 14'. It should be understood that the schematic illustrated in FIGURE 1 is only by way of example and that persons of ordinary skill in the art may use other means to stop the driving of the unitized windup devices or to provide alarms, or the like, in case of a malfunction of any one device.

FIGURE 3 shows the various details for mounting the flanged guide roll 41 so that it will perform its function of interrupting light beam 14 if tension T is either absent or below the minimum predetermined winding tension for the unitized windup device. As seen in FIGURE 3, flanged guide roll 41 is mounted on the outer race of ball bearing 42. The inner race of ball bearing 42 is mounted on hubs 43 and 44. During winding, the flanged roll 41 is rotated on bearing 42 while defining a path for the moving web S which is partially wrapped about and engaged by the flanged guide roll 41. Hubs 43 and 44 are pivoted to the housing formed by plates 17 on pivot pin 45 which is off center from the center of the guide roll 41. Torsion spring 46 urges hubs 43 and 44, and the bearings 42 and guide roll 41 mounted thereon, toward a second position as shown in full lines on FIGURE 1 wherein guide roll 41 interrupts light beam 14'. Torsion spring 46 acts to absorb slight tension fluctuations introduced into the webs during winding. The guide roll 41 pivots clockwise around pin 45 when tension T decreases. The pinch roller 28 shown in FIG. 1 has an associated ratchet and can only rotate in the clockwise direction. Thus, when a web S is pinched between roller 28 and guide roll 41, when the latter pivots in the clockwise direction, the web S will be held in the clockwise unitized windup device. This has been found to be advantageous when only the leading end of a web S lies under the flanged idler drum 19, such as during the cleaning cycle described in the aforementioned copending US. application entitled Automatic Winding Apparatus and Methods. The ends of torsion spring 46 are connected to hubs 43 and 44 at holes 43 and 44', respectively. Torsion spring 46 has a U-shaped loop 46' which is engaged by an adjusting pin 49 which is rigidly attached to adjusting screw 48 and rotatable spacer 47. Adjusting screw 48 and spacer 47 are locked in the desired position by locking screw 50. Normally, after the leading end 24 of web S is cinched onto core 22, tension T, as seen in FIG. 1, is developed in web S and the tensioned web S provides a force pulling the flanged guide roll 41 to the left to a first position as seen in dotted lines in FIGURE 1. During assembly of the windup device, the adjusting screw 48 in FIGURE 3 is turned and the torsion spring 46 is adjusted so that the guide roll 41 will remain in its first position under the influence of the force from the tensioned web during winding.

In one installation embodying the present invention, webs of 16 mm. photographic film were simultaneously wound to form successive rolls of 18 inches in diameter. The winding was accomplished in a darkened room and a collimated infrared light beam was utilized to detect when the tension in any of the webs dropped below a predetermined minimum of about 12 oz. per web during winding, or failed to develop during startup. When tension was below the predetermined minimum for a time indicative of a malfunction, the winding apparatus was automatically stopped to avoid damage to the apparatus or waste of the photographic product.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

What is claimed is:

1. An apparatus for winding simultaneously at least a first plurality of webs and for subsequently winding simultaneously at least a second plurality of webs, said apparatus including:

means for winding said webs under a predetermined minimum tension when forming respective convolutely wound rolls therefrom; and

means for sensing when the tension in at least one of said webs is below said predetermined minimum tension, said sensing means comprising:

a plurality of rotable guide rolls for engaging respective webs of said first plurality and defining paths for such webs during winding, and subsequently, for engaging respective Webs of said second plurality and defining paths for such webs during winding, the respective axes of rotation of said guide rolls being supported in respective first positions by the respective forces exerted on said guide rolls by said webs under said predetermined minimum tension;

means mounting said guide rolls for rotation about said axes and for movement of said axes from said first position to respective second positions when the tension of said respective webs is less than said predetermined minimum;

means operatively associated with said mounting means for urging said axes toward said second positions; and

means for detecting When the axis of at least one guide roll moves to its second position.

2. The invention of claim 1 wherein said means for Winding said webs includes means for supporting respective rolls during forming by partially embracing the sides thereof.

3. The invention of claim 1 wherein said means for winding said webs includes means for supplying respective cores onto which said rolls are formed.

4. The invention of claim 3 wherein said means for winding said webs includes means for guiding the respective leading ends of said webs onto said cores to initiate winding of said webs.

5. The invention of claim 1, 2, 3, or 4, wherein said detecting means includes a photoelectric cell which is illuminated by a light beam from a source when all of the guide rolls axes are in their first positions, and which receives no illumination from said source when at least one guide rolls axis is in its second position wherein said guide roll interrupts the light beam.

6. The invention of claim 1, 2, 3, or 4 further including means, responsive to said detecting means for stopping the winding apparatus when the axis of at least one guide roll moves to its second position.

7. The invention of claim 1, 2, 3, or 4, wherein said detecting means includes a photoelectric cell which is illuminated by a light beam from a source when all of the guide rolls axes are in their first positions and which receives no illumination from said source when at least one guide rolls axis is in its second position wherein said guide roll interrupts the light beam, and; means, responsive to said photoelectric cell, for stopping the winding apparatus when said last-named guide roll interrupts said light beam.

8. An apparatus for winding simultaneously at least a first plurality of elongated flexible elements during a winding phase and for subsequently winding simultaneously at least a second plurality of elongated flexible elements during another winding phase which follows an automatic start-up phase of operation, said apparatus including:

means for winding every one of said flexible elements individually under a predetermined minimum tension when forming respective convolutely wound rolls therefrom, and;

means for sensing when the tension in at least one of said elongated flexible elements is below said predetermined minimum tension, said sensing means comprising:

a plurality of rotatable guide rolls for engaging respective elongated flexible elements of said first plurality and defining paths for such elements during winding, and subsequently, for engaging respective elongated flexible elements of said second plurality and defining paths for such elements during winding, the respective taxes of rotation of said guide rolls being supported in respective first positions by the respective forces exerted on said guide rolls by said elements under said predetermined minimum tension;

means mounting said guide rolls for rotation about said axes and for movement of said axes from said first positions to respective second positions when the tension of said respective elements is less than said predetermined minimum;

means operatively associated with said mounting means for urging said axes toward said second positions; and

means for detecting when the axis of at least one guide roll moves to said second position during either the winding or start-up phases of operation of said apparatus.

References Cited UNITED STATES PATENTS 2,275,093 3/1942 Spangler 24275.2 X 2,723,085 11/1955 Conti 24256.9 2,772,551 12/1956 Haas 2006l.18 X 2,849,193 8/1958 Pauls et al 242-71. 8 3,092,764 6/ 1963 Cooper.

3,239,155 3/1966 Kinoshita 242-56 X. 3,305,896 2/1967 Rayfield et al. ZOO-61.18 X 3,330,016 7/1967 Smith et al. ZOO-61.18 X 3,386,679 6/1968 Foulon et al 24275.2 X

STANLEY N. GILREATH, Primary Examiner US. Cl. X.R. 200-61.18 

